[Threedimensional cephalometric contribution to the study of mandibulo-facial dysplasias].

The cephalometric particulars of the dysplastic syndrome of the first visceral segment, the dysostosis mandibulofacialis Franceschetti-Zwahlen were investigated. Ten patients were found with the identical symptom of a typical, uni- or bilateral microtia of the external ear. The cephalometric characteristics of the syndrome may be summarized as follows: - retroposition of the middle face - retroposition of maxilla and mandible - retrorotation of the mandible - reduction of vertical and lateral dimension of the face - reduction of transverse diameter of both dental arches - shortened mandibular base - both halves of the face are affected, but more so the half with microtia - the chin is deflected toward the affected side. Most of these symptoms must be attributed to disturbed organogenesis. With the rest of them, functional adaptation cannot be exluded.